The day before.
Link, who had just hours ago became the sole inherit of the Triforce and all its power was at his home, Kokiri Forest, before the now dead Deku Tree. Wielding the power of the Triforce was absolutely unrivaled by any amount of power in history. Yes, Link thought, how marvelous it all really was. He could do anything now, he was bound by nothing. He never had to risk his neck battling against his foes, and he never had to have the weight of the world put on his shoulders, because he carried all the powers of the Heaven and Earth in his hands, now. Yes indeed, the Triforce was certainly his own personal skeleton key to unlock the doors leading to all of his wildest fantasies and dreams.
And imagine is just what Link did. He pictured himself surrounded by beautiful woman, doing things he liked to do with beautiful woman. Link imagined having all the money in the world, and buying everything that he wanted. And Link sat and pondered all the places in his mind that he never dared to think about. And quickly, like a sudden gust of a strong wind, his mind filled with dark fantasies, thoughts he had never dared share with anyone, or even privately contemplate to the degree he was contemplating them now.
Link was not born an evil person either, by any means. He may have been eccentric, and his natural born power was just a stroke of luck, but he was born with a kind heart. It was not entirely the power of the Triforce that drove him to insanity; the power only amplified what had already manifested its self. Link had, unquestionably had the burden of the world on his shoulders, which was too much for almost any man to bear, and at the time he was just a small child, still learning morals, and the difference between right and wrong. So, inevitably, all the fighting Link had done turned him into quite a cruel and substantially insane man, although no one knew it, or had the slightest suspicion of it. Not even Link himself, which is perhaps most terrifying.
Hyrule Castle, to visit Princess Zelda, would be the very next place Link would go to. Of all the things Link was imaging, he didn't imagine Zelda would like the visit Link was about to pay her.